I think anyone who thinks its a good idea to try and keep updating and fixing X11 should drop everything and have a watch of this panel:

The Real Story Behind Wayland and X - Daniel Stone (linux.conf.au 2013) https://www.youtube.com/watch?v=RIctzAQOe44

It clarifies, from the people who actually get their hands dirty with X, why it's not such a good idea to keep evolving X11, why most of the things you think is handled by X are actually handled by many different components that are also used by Wayland environments and why so much of X11's design has fallen into disuse, and why X actually got "better" for a while (hint: it's because desktop environments depends on it less).

It is a shame that wayland took this long and had to deal with so much technical debt, and maybe didn't take the best approach for everything, but as someone who has been using linux desktop since 2006 and always thought it was very flaky and unprofessional... I say good riddance to X11 and am happy to how much more stable and polished modern linux desktop is, mainly on wayland but even including how much better it is to use modern environments under X11.